xref: /netbsd-src/external/bsd/openldap/dist/contrib/slapd-modules/passwd/apr1.c (revision 549b59ed3ccf0d36d3097190a0db27b770f3a839)
1 /*	$NetBSD: apr1.c,v 1.2 2021/08/14 16:14:52 christos Exp $	*/
2 
3 /* $OpenLDAP$ */
4 /*
5  * This file is derived from OpenLDAP Software. All of the modifications to
6  * OpenLDAP Software represented in the following file were developed by
7  * Devin J. Pohly <djpohly@gmail.com>. I have not assigned rights and/or
8  * interest in this work to any party.
9  *
10  * The extensions to OpenLDAP Software herein are subject to the following
11  * notice:
12  *
13  * Copyright 2011 Devin J. Pohly
14  * Portions Copyright 2011 Howard Chu
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted only as authorized by the OpenLDAP Public
17  * License.
18  *
19  * A portion of this code is used in accordance with the Beer-ware License,
20  * revision 42, as noted.
21  *
22  */
23 
24 #include <sys/cdefs.h>
25 __RCSID("$NetBSD: apr1.c,v 1.2 2021/08/14 16:14:52 christos Exp $");
26 
27 #include "portable.h"
28 
29 #include <lber.h>
30 #include <lber_pvt.h>
31 #include "lutil.h"
32 #include "lutil_md5.h"
33 #include <ac/string.h>
34 
35 #include <assert.h>
36 
37 /* the only difference between this and straight PHK is the magic */
38 static LUTIL_PASSWD_CHK_FUNC chk_apr1;
39 static LUTIL_PASSWD_HASH_FUNC hash_apr1;
40 static const struct berval scheme_apr1 = BER_BVC("{APR1}");
41 static const struct berval magic_apr1 = BER_BVC("$apr1$");
42 
43 static LUTIL_PASSWD_CHK_FUNC chk_bsdmd5;
44 static LUTIL_PASSWD_HASH_FUNC hash_bsdmd5;
45 static const struct berval scheme_bsdmd5 = BER_BVC("{BSDMD5}");
46 static const struct berval magic_bsdmd5 = BER_BVC("$1$");
47 
48 static const unsigned char apr64[] =
49 	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
50 
51 #define APR_SALT_SIZE	8
52 
53 /* The algorithm implemented in this function was created by Poul-Henning
54  * Kamp and released under the following license:
55  * ----------------------------------------------------------------------------
56  * "THE BEER-WARE LICENSE" (Revision 42):
57  * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
58  * can do whatever you want with this stuff. If we meet some day, and you think
59  * this stuff is worth it, you can buy me a beer in return Poul-Henning Kamp
60  * ----------------------------------------------------------------------------
61  */
do_phk_hash(const struct berval * passwd,const struct berval * salt,const struct berval * magic,unsigned char * digest)62 static void do_phk_hash(
63 	const struct berval *passwd,
64 	const struct berval *salt,
65 	const struct berval *magic,
66 	unsigned char *digest)
67 {
68 	lutil_MD5_CTX ctx, ctx1;
69 	int n;
70 
71 	/* Start hashing */
72 	lutil_MD5Init(&ctx);
73 	lutil_MD5Update(&ctx, (const unsigned char *) passwd->bv_val, passwd->bv_len);
74 	lutil_MD5Update(&ctx, (const unsigned char *) magic->bv_val, magic->bv_len);
75 	lutil_MD5Update(&ctx, (const unsigned char *) salt->bv_val, salt->bv_len);
76 	/* Inner hash */
77 	lutil_MD5Init(&ctx1);
78 	lutil_MD5Update(&ctx1, (const unsigned char *) passwd->bv_val, passwd->bv_len);
79 	lutil_MD5Update(&ctx1, (const unsigned char *) salt->bv_val, salt->bv_len);
80 	lutil_MD5Update(&ctx1, (const unsigned char *) passwd->bv_val, passwd->bv_len);
81 	lutil_MD5Final(digest, &ctx1);
82 	/* Nom start mixing things up */
83 	for (n = passwd->bv_len; n > 0; n -= LUTIL_MD5_BYTES)
84 		lutil_MD5Update(&ctx, digest,
85 				(n > LUTIL_MD5_BYTES ? LUTIL_MD5_BYTES : n));
86 	memset(digest, 0, LUTIL_MD5_BYTES);
87 	/* Curiouser and curiouser... */
88 	for (n = passwd->bv_len; n; n >>= 1)
89 		if (n & 1)
90 			lutil_MD5Update(&ctx, digest, 1);
91 		else
92 			lutil_MD5Update(&ctx, (const unsigned char *) passwd->bv_val, 1);
93 	lutil_MD5Final(digest, &ctx);
94 	/*
95 	 * Repeatedly hash things into the final value. This was originally
96 	 * intended to slow the algorithm down.
97 	 */
98 	for (n = 0; n < 1000; n++) {
99 		lutil_MD5Init(&ctx1);
100 		if (n & 1)
101 			lutil_MD5Update(&ctx1,
102 				(const unsigned char *) passwd->bv_val, passwd->bv_len);
103 		else
104 			lutil_MD5Update(&ctx1, digest, LUTIL_MD5_BYTES);
105 
106 		if (n % 3)
107 			lutil_MD5Update(&ctx1,
108 				(const unsigned char *) salt->bv_val, salt->bv_len);
109 		if (n % 7)
110 			lutil_MD5Update(&ctx1,
111 				(const unsigned char *) passwd->bv_val, passwd->bv_len);
112 
113 		if (n & 1)
114 			lutil_MD5Update(&ctx1, digest, LUTIL_MD5_BYTES);
115 		else
116 			lutil_MD5Update(&ctx1,
117 				(const unsigned char *) passwd->bv_val, passwd->bv_len);
118 		lutil_MD5Final(digest, &ctx1);
119 	}
120 }
121 
chk_phk(const struct berval * magic,const struct berval * passwd,const struct berval * cred,const char ** text)122 static int chk_phk(
123 	const struct berval *magic,
124 	const struct berval *passwd,
125 	const struct berval *cred,
126 	const char **text)
127 {
128 	unsigned char digest[LUTIL_MD5_BYTES];
129 	unsigned char *orig_pass;
130 	int rc;
131 	struct berval salt;
132 	size_t decode_len = LUTIL_BASE64_DECODE_LEN(passwd->bv_len);
133 
134 	/* safety check */
135 	if (decode_len <= sizeof(digest))
136 		return LUTIL_PASSWD_ERR;
137 
138 	/* base64 un-encode password hash */
139 	orig_pass = (unsigned char *) ber_memalloc(decode_len + 1);
140 
141 	if (orig_pass == NULL)
142 		return LUTIL_PASSWD_ERR;
143 
144 	rc = lutil_b64_pton(passwd->bv_val, orig_pass, decode_len);
145 
146 	if (rc <= (int) sizeof(digest)) {
147 		ber_memfree(orig_pass);
148 		return LUTIL_PASSWD_ERR;
149 	}
150 
151 	salt.bv_val = (char *) &orig_pass[sizeof(digest)];
152 	salt.bv_len = rc - sizeof(digest);
153 
154 	do_phk_hash(cred, &salt, magic, digest);
155 
156 	if (text)
157 		*text = NULL;
158 
159 	/* compare */
160 	rc = memcmp((char *) orig_pass, (char *) digest, sizeof(digest));
161 	ber_memfree(orig_pass);
162 	return rc ?  LUTIL_PASSWD_ERR : LUTIL_PASSWD_OK;
163 }
164 
chk_apr1(const struct berval * scheme,const struct berval * passwd,const struct berval * cred,const char ** text)165 static int chk_apr1(
166 	const struct berval *scheme,
167 	const struct berval *passwd,
168 	const struct berval *cred,
169 	const char **text)
170 {
171 	return chk_phk(&magic_apr1, passwd, cred, text);
172 }
173 
chk_bsdmd5(const struct berval * scheme,const struct berval * passwd,const struct berval * cred,const char ** text)174 static int chk_bsdmd5(
175 	const struct berval *scheme,
176 	const struct berval *passwd,
177 	const struct berval *cred,
178 	const char **text)
179 {
180 	return chk_phk(&magic_bsdmd5, passwd, cred, text);
181 }
182 
hash_phk(const struct berval * scheme,const struct berval * magic,const struct berval * passwd,struct berval * hash,const char ** text)183 static int hash_phk(
184 	const struct berval *scheme,
185 	const struct berval *magic,
186 	const struct berval *passwd,
187 	struct berval *hash,
188 	const char **text)
189 {
190 	unsigned char digest_buf[LUTIL_MD5_BYTES];
191 	char salt_buf[APR_SALT_SIZE];
192 	struct berval digest;
193 	struct berval salt;
194 	int n;
195 
196 	digest.bv_val = (char *) digest_buf;
197 	digest.bv_len = sizeof(digest_buf);
198 	salt.bv_val = salt_buf;
199 	salt.bv_len = APR_SALT_SIZE;
200 
201 	/* generate random salt */
202 	if (lutil_entropy( (unsigned char *) salt.bv_val, salt.bv_len) < 0)
203 		return LUTIL_PASSWD_ERR;
204 	/* limit it to characters in the 64-char set */
205 	for (n = 0; n < salt.bv_len; n++)
206 		salt.bv_val[n] = apr64[salt.bv_val[n] % (sizeof(apr64) - 1)];
207 
208 	do_phk_hash(passwd, &salt, magic, digest_buf);
209 
210 	if (text)
211 		*text = NULL;
212 
213 	return lutil_passwd_string64(scheme, &digest, hash, &salt);
214 }
215 
hash_apr1(const struct berval * scheme,const struct berval * passwd,struct berval * hash,const char ** text)216 static int hash_apr1(
217 	const struct berval *scheme,
218 	const struct berval *passwd,
219 	struct berval *hash,
220 	const char **text)
221 {
222 	return hash_phk(scheme, &magic_apr1, passwd, hash, text);
223 }
224 
hash_bsdmd5(const struct berval * scheme,const struct berval * passwd,struct berval * hash,const char ** text)225 static int hash_bsdmd5(
226 	const struct berval *scheme,
227 	const struct berval *passwd,
228 	struct berval *hash,
229 	const char **text)
230 {
231 	return hash_phk(scheme, &magic_bsdmd5, passwd, hash, text);
232 }
233 
init_module(int argc,char * argv[])234 int init_module(int argc, char *argv[]) {
235 	int rc;
236 	rc = lutil_passwd_add((struct berval *) &scheme_apr1, chk_apr1, hash_apr1);
237 	if ( !rc )
238 		rc = lutil_passwd_add((struct berval *) &scheme_bsdmd5,
239 			chk_bsdmd5, hash_bsdmd5);
240 	return rc;
241 }
242